Mitochondrial genomics of fishes : determination and analysis of complete nucleotide sequence of the mtDNA

鱼类线粒体基因组学：线粒体DNA完整核苷酸序列的测定和分析

基本信息

批准号：
12460083
负责人：
NISHIDA Mutsumi
金额：
$ 10.11万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

Genetic information encoded on the DNA provides important makers for estimating genealogy, population structure, phylogeny, and evolution of organisms. However, it has become apparent that obtaining enough genetic information from the nuclear genome is a rather difficult task because the nuclear genome is a very complex entity in which many genes are duplicated. In this context, preferable is the mitochondrial (mt) genome because of its simplicity. Mitochondrial genomes (and their genes) in "advanced" animals are homologous undoubtedly and are inherited without recombination, and thus they are attractive for phylogenetic and population genetic researches as an important information source. In this project, we determined and compared complete nucleotide sequences of the mt genomes from many fishes representing major lineages of fish, and then tried to estimate comprehensive phylogenetic framework of teleostean fishes on the basis of the resultant large DNA dataset.Thanks to further development of experimental procedures, equipments, and our research group, we have sequenced complete mt genomes from more than 200 species, which number exceeded ten times as many as what we first aimed to sequence. From the sequence data, various new types of gene arrangement deviated from that of the common vertebrate were found. Phylogenetic analysis of the sequence data also provided many new findings on the relationships among basal teleosts. One of important findings is that the Elopomorpha which includes eels is found to be much more basal in the teleostean phylogeny than assumed previously.

DNA 上编码的遗传信息为估计生物体的谱系、种群结构、系统发育和进化提供了重要的依据。然而，很明显，从核基因组中获取足够的遗传信息是一项相当困难的任务，因为核基因组是一个非常复杂的实体，其中许多基因是重复的。在这种情况下，更可取的是线粒体（mt）基因组，因为它简单。 “高级”动物的线粒体基因组（及其基因）无疑是同源的，并且无需重组即可遗传，因此它们作为重要的信息来源对系统发育和群体遗传学研究很有吸引力。在这个项目中，我们确定并比较了代表鱼类主要谱系的许多鱼类的mt基因组的完整核苷酸序列，然后尝试在所得的大型DNA数据集的基础上估计硬骨鱼的综合系统发育框架。凭借实验程序、设备和我们的研究小组，我们已经对200多个物种的完整mt基因组进行了测序，数量超过了我们最初计划测序的十倍。从序列数据来看，发现了多种与常见脊椎动物不同的新型基因排列。序列数据的系统发育分析也提供了许多关于基础硬骨鱼之间关系的新发现。重要的发现之一是，包括鳗鱼在内的 Elopomorpha 在硬骨动物系统发育中比之前假设的更为基础。